Six Reasons for Low Energy Runs

I'm training for my first half-marathon, and my long runs have been great but I feel completely drained in my runs during the week. Any advice? Thanks. - Christi

I'm glad you asked this question, as light fatigue and intermittent energy drain throughout the season is a normal part of training for a half or full marathon. However, continuous energy drain mid-week means there is something out of balance.An easy way to detect what may be causing the drain is to evaluate the many variables that contribute to the training process. One by one, you can review this list to identify the energy suckers in your program:

Training Effort. Are you training by effort or pace? A common mistake is to train too fast or too hard which leads to a slower recovery process. This is especially true when training in the record heat this summer. Invest in training at a truly easy, conversational effort for your long runs and let your pace be only the outcome. Avoid worrying about pace, as the long run is all about teaching your body to run longer and stronger. This is also the case when training during the week. If it is 85 degrees and humid, your normal running pace will feel much harder (more taxing). Train by your effort (how you feel), and you'll get in a quality workout, recover faster, and regain your energy.

Quantity of long runs. A solid half-marathon training program should include a variety of ingredients. When too many long runs are performed on back-to-back weekends, it, too, can cause energy drain. The long run progression should build and cut back regularly throughout the season. The cutback week with a shorter long run is, in its own way, a rest from the demands of building mileage. Without it, your body can experience fatigue. However, this usually is expressed in a continuous low energy level.

Progression of long runs. If the progression of long-run mileage is too demanding, it can cause fatigue. It is vital to efficient recovery and adaptation (growth) to start from where you are in the beginning of the training plan and progress gradually from there. If you are jumping up by more than one to two miles, this may be your culprit. It is better to go into race day with a shorter long run under your belt than to progress too quickly and toe the line tired.

Fuel Replenishment. You are what you eat, and if you aren't fueling with enough calories after long runs, it can create an energy void. This is especially true when runners are trying to train for a race and lose weight at the same time. Keep a fuel log and track the calories going in and out to optimally balance your caloric energy. This will also help dial in the quality of fuel as well. I use a free log called Fitday.com because it allows you to evaluate your total energy expenditure (training, lifestyle, and what you need to breathe) with your caloric consumption. If you drop much below a 15% deficit it can reduce your metabolic efficiency and create a lot of problems including low energy. For example, if you burn 2800 calories but take in only 1600 during the day, this creates a 42% deficit in energy lost. This will negatively affect your body's ability to recovery from the demands of your workouts. (Disclosure: I have no affiliation with Fitday - I just believe it's a useful tool for runners.)

Sleep. A vast number of studies are validating the importance of sleep for optimal life performance. It's even more important when you are pushing your body in training. American women's marathon record-holder Deena Kastor noted on her website after having her first child, "Gone are the days of 12 hours of sleep." When you push, you need quality sleep to recover. One of the best benefits of long runs is the permission to nap.

Cross-training too hard. I'm an advocate for weaving in cross-training for a variety of reasons, but when you push too hard, it can affect your runs. For example, CrossFit is a great workout, but it is done at an extremely high intensity. The combination of your half-marathon training and very high intensity cross-training sessions can create energy lows. It's all about balancing training stress and recovery to reach the finish line successfully.